* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
    font-family: 'Segoe UI', Tahoma, Geneva, Verdana, sans-serif;
}

body {
    background-color: #f0f2f5;
    display: flex;
    justify-content: center;
    align-items: center;
    min-height: 100vh;
}

.container {
    width: 100%;
    max-width: 450px;
    padding: 20px;
}

.card {
    background-color: white;
    border-radius: 10px;
    box-shadow: 0 4px 8px rgba(0, 0, 0, 0.1);
    overflow: hidden;
}

.card-header {
    background-color: #4a69bd;
    color: white;
    padding: 20px;
    text-align: center;
}

.card-header h2 {
    font-size: 1.5rem;
    font-weight: 500;
}

.card-body {
    padding: 25px;
}

.form-group {
    margin-bottom: 20px;
}

.form-row {
    display: flex;
    gap: 15px;
}

.form-group.expiry {
    flex: 1;
}

.form-group.cvv {
    flex: 0.5;
}

label {
    display: block;
    margin-bottom: 8px;
    font-size: 0.9rem;
    color: #555;
    font-weight: 500;
}

input {
    width: 100%;
    padding: 12px 15px;
    border: 1px solid #ddd;
    border-radius: 5px;
    font-size: 1rem;
    transition: border-color 0.3s;
}

input:focus {
    outline: none;
    border-color: #4a69bd;
    box-shadow: 0 0 0 2px rgba(74, 105, 189, 0.2);
}

input::placeholder {
    color: #bbb;
}

.btn-submit {
    width: 100%;
    padding: 14px;
    background-color: #4a69bd;
    color: white;
    border: none;
    border-radius: 5px;
    font-size: 1rem;
    cursor: pointer;
    transition: background-color 0.3s;
}

.btn-submit:hover {
    background-color: #3a539b;
}

.btn-submit:active {
    transform: translateY(1px);
}